UK – Researchers have identified an outbreak of foodborne infection in the UK during April 2023 as a Salmonella enteritidis infection, with potential ties to imported eggs from Poland.
The outbreak, which caused widespread concern and prompted immediate investigations, has shed light on the importance of rigorous food safety measures and international cooperation in preventing such incidents.
When an outbreak linked to a restaurant was reported to the UK Health Security Agency (UKHSA) East of England Health Protection Team (HPT), researchers sprang into action.
Armed with the powerful tool of whole genome sequencing (WGS), they delved deep into the genetic makeup of the Salmonella enteritidis bacteria responsible for the outbreak.
Published in the journal Eurosurveillance, the study’s results confirmed the presence of the Salmonella enteritidis infection.
Moreover, the research team discovered that all cases belonged to a 5-single nucleotide polymorphism (SNP) cluster, which formed part of a larger, genomically diverse 10-SNP cluster observed in several countries. This genomic pattern provided vital clues for tracing the origin and spread of the infection.
As the investigation unfolded, the research team uncovered compelling evidence suggesting links between the outbreak and imported eggs from Poland.
These eggs, believed to be the possible source of the contamination, raised serious concerns about the need for stricter food safety regulations and cross-border cooperation to safeguard public health.
During their comprehensive investigation, the researchers scrutinized a total of 47 confirmed cases, of which 25 were directly linked to the implicated restaurant. Additionally, 18 probable cases had exposure to the restaurant.
This data reinforced the association between the outbreak and the dining establishment, underscoring the urgency of implementing preventive measures.
Eggs or Chicken: Identifying the culprit
While eggs or chicken were suspected as the most likely culprits behind the outbreak, the research team faced challenges in definitively attributing the source.
Despite the complexity of the investigation, the researchers’ relentless efforts underscored the importance of meticulous food chain analysis to safeguard public health.
As health authorities remain vigilant in combating foodborne illnesses, this outbreak serves as a stark reminder of the global nature of food supply chains. The need for close international cooperation in monitoring and regulating food imports is more critical than ever.
New detection technique
Shell eggs are a frequent source of infection for S. enteritidis, one of the serovars that cause foodborne salmonellosis most frequently worldwide.
Even though checking for viable S. enteritidis in shell eggs is crucial for early warnings and making sure that contaminated food does not reach the market, the traditional “gold standard” culture-based testing methods demand numerous time-consuming stages and employees with specialized technical expertise.
It typically takes five to seven days for a culture-based system that used live isolates to confirm the presence of S. enteritidis.
Researchers from the National Center for Food Science of the Singapore Food Agency and the National University of Singapore have recently created a real-time polymerase chain reaction (PCR) method for the detection of viable Salmonella enteritidis contamination in shell eggs that, if integrated, would speed up the current Salmonella testing procedure.